CVE-2021-33790 json
The RebornCore library before 4.7.3 allows remote code execution because it deserializes untrusted data in ObjectInputStream.readObject as…
published 5y ago modified 4mo ago also EUVD-2021-20467
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.8%
- EPSS 2.8% chance of exploitation in 30 days, percentile 86%
- public exploits
- 0
- none known
Summary
The RebornCore library before 4.7.3 allows remote code execution because it deserializes untrusted data in ObjectInputStream.readObject as part of reborncore.common.network.ExtendedPacketBuffer. An attacker can instantiate any class on the classpath with any data. A class usable for exploitation might or might not be present, depending on what Minecraft modifications are installed.
Patch / fix
- techreborn reborncore 3.19.5, 4.2.10, 4.7.3
Is CVE-2021-33790 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
2.84% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
curseforge.com
/minecraft/mc-mods/reborncore
product, third-party-advisory
-
vuln.ryotak.me
/advisories/45
third-party-advisory
-
github.com
/TechReborn/RebornCore/security/advisories/GHSA-r7pg-4xrf-7mrm
third-party-advisory
Sources
- CVE List CVE-2021-33790
- NVD CVE-2021-33790
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.